Burial vaults have commonly been made of a cement composition which is known to be pervious to water. Various types of lining materials have been used to seal the vaults in order to make them impervious to water. Special handling techniques and special bonding materials have been required in order to make this type of a vault. The cement composition vaults also are subject to considerable pressure from the surrounding soil after they have been placed in the ground and require reinforcement in order to prevent collapse of the vault. Efforts to increase the strength of the concrete vaults have been directed to the inclusion of reinforcing wires within the cement composition as well as the use of metallic liners both on the inside and outside of the vault. However, it is generally known that metallic materials are subject to chemical attack from the materials in the surrounding soil and have a relatively short life.
One of the most recent attempts to provide a burial vault having the capability of being impervious to water is shown in the Chandler patent 3,439,461, issued on April 22, 1969 entitled "Burial Vaults". This type of a vault is generally formed by casting the cement composition into the space between the inner liner and the outer mold. An adhesive bonding material is precoated on the inner surfaces of the liner and the cement composition added while the adhesive material is still wet and tacky. Special bonding materials have been used in order to obtain a satisfactory bond between the liner and the cement composition. Although this type of a vault provides a water-tight enclosure and protection from chemical attack, the special handling techniques and adhesive material add to the overall cost.